Generally speaking, endoscopes are thin tubular cameras that are typically utilized in the diagnosis of a disease. These cameras are usually inserted into the body cavity either through a natural opening like the mouth or the anus or through a tiny incision made into the skin. The endoscopes are extensively used intra-operatively to assist the surgeon in visualizing the anatomy of interest to perform the procedure and to avoid damage to critical surrounding organs. Most of the endoscopes available in the market to date can be classified into either a rigid or a flexible endoscope. Commonly found endoscopes are available with two-dimensional cameras and have limited image resolution and depth perception. These endoscopes are disorienting to the surgeon after a prolonged use and lack the natural spectrum of direct human visualization.
Recently some manufacturers have started producing three-dimensional (stereoscopic) endoscopes. The optical version of these endoscopes use two tubular lenses inside a long shaft and two standard cameras mounted outside of the body. The next generation of stereo endoscopes employs custom designed semiconductor circuitry mounted at the tip of the endoscope (inside the body) that is capable of producing stereo images. In these endoscopes, either two close proximity mounted chips or a special chip with a large array of micro lenses manufactured onto the chip is utilized to create stereo images. In addition, such endoscopes also include LED or fiber optic light sources for illumination. FIG. 1 shows a conventional stereo endoscope.
U.S. Pat. No. 4,862,873 issued to Yajima et al. discloses a stereo endoscope that utilizes two thin optical guides mounted in a tubular shaft and two CCD image sensors mounted outside the body to create three-dimensional images of the organ.
U.S. Patent application US2002/0007110, to Irion discloses a stereo endoscope that utilizes two lateral mounted cameras with a flexible endoscope head to create three-dimensional images of the organ.
The field of surgical intervention has evolved from open invasive approach to the paradigm of minimally invasive surgery due to its benefits to the patients and the healthcare system. From the surgeon's perspective, the transition has resulted in a procedure with limited and un-natural field of view and surgical skills that have a steep learning curve. The existing three-dimensional endoscopes have resulted in incremental enhancement to the visualization, but have failed to match the natural spectrum of direct human visualization. The 3D depth perception of these endoscopes is also constrained by the limited physical separation between the two cameras. Additionally, it is projected that the surgical paradigm will shift from the three or four incision laparoscopic approach to a single incision (single port access (SPA)) surgery.
Thus, there is a need and good market potential for improved endoscopes that can provide a better visualization of the surgical site.